Sound-transmitting means



H. J. DURBOROW AND B. L. WINDERS.

SOUND TRANSMITTING MEANS.

APPLICATION FILED MAR. III. 1920.

2 SHEETSSHEET I.

H. J. DURBOROW AND B. L. WINDERS SOUND TRANSMITTING MEANS.

APPLICATION FILED MAR. 18, 1920.

Patented June 6, 1922.

2 SHEETS-SHEET 2.

air/17121011 UNITED STATES PATENT -OFFICE.

HARRY J'. DURBOROW AND BAYARD L. WINDERS, OF II-IILADELPHIA, PENNSYLVANIA SOUND-TRANSMITTING MEANS.

Specification of Letters Patent.

Patented June 6, 1922.

Application filed March 18, 1920. Serial No. 366,818.

One object of our invention is to provide sound transmitting means fortalking machines which will include a resonator and amplifier havingvibratory portions of such character as to allow all complex sound tofind sympathetic or suitably formed vibratory parts which willaccurately and discriminately resound and amplify sound waves impingingupon them and thereby reproduce an audible analysis of complex sound.Thus by the use of our present invention on talking machines the soundsof voices, instruments or the like which were originally recorded in therecord will be reproduced in such manner as to be readily distinguishedone from another without any blurring or false intermingling of soundswhich were not originally present or record ed in the record.

Another object is to so construct said means that it can be easily andcheaply made and embodied in a talkingmachine.

These objects, and other advantageous ends which will be describedhereinafter, we attain in the following manner, reference being had tothe accompanying drawings in Which Figure 1 is a top plan view showingsound transmitting means made in accordance with our invention andillustrated in connection with a portion of a cabinet of a talkingmachine,

Figure 2 is a sectional elevation taken on the line 22 of Figure 1,

Figure 3 is an end View illustrating our invention,

Figure 4 is a side view of one of a num-' ber of sections of anamplifying resonator which forms a part of our invention,

Figure 5 is'a top plan view of Figure 4,,

Figure 6 is an end view of Figure 4,

Figures 7 and 8 are perspective views of certain of the elements of ourinvention, and

Figure9 is a fragmentary section taken on the line 9-9 of Figure 2.

Referring to the drawings, 10 represents a talking machine cabinet whichmay be of any suitable construction providing a chamber 11 and having arear board 12, and a front board 13 which is provided with an opening14:.

We provide a block 15 which may be made from a piece of wood square incross section as shown in Figures 1 and 7 and downwardl through thisblock is bored a passage 16. his passage can be bored with a drill bithaving a lower chamfered end so that the end of the bit will produce abeveled surface 17 above the bottom 18 of the block 15. Another passage19 is drilled into the front face 20 of the block and this passage canbe drilled with the same bit which is used for the passage 16 and atright angles to the passage 16 as clearly shown in Figure 2; the bottomof the passage 19 beingcoincident with the bottom of the passage 16; thepassages 16 and 19 joining each other in the manner of a cylindricalintersection. The rear of the block 15 can be glued or otherwisesuitably secured to the rear board 12 of the cabinet 10. An extension21, which may be made of a block of wood square in cross section, isglued or otherwise suitably secured to the front face 20 of the block 15and this extension 21 has a flange 22 in the form of a flat projectionwhich engages the bottom of the block 15 and extends to the rear board12 of the cabinet. The extension 21 has a bore 23 which is preferablymade by a drill bit of larger diameter than that used to make thepassages 16 and 19 and the drill bit used for the passage 23 is alsopreferably provided with a chamfered end so as to provide a beveledportion 24 of the passage 23; the smallest diameter of said bevelportion being substantially equal to the diameter of the passage 19 andin axial alignment therewith. The forward part of the passage 23 flaresoutwardly as shown at 25 and the outer surface of the extension 21adjacent the forward end thereof is turned to form a recess 26 which iscircular in cross section and which tapers rearwardly and intercepts aforward surface 21 of the extension 21. An amplifying resonator 27flares outwardly from the extension 21 and is so constructed as to haveparts of different elastic resistance for co-ac-ting with sound wavesand we have illustrated one manner of producing an amplifying resonatorhaving said latter mentioned characteristics. in the present instancesaid resonator is made up of tour sections 2 25). ll) and 31 ot resonatewood. Each of these sections is cut out of a block of wood into theshape shown in Figures 5 to c inclusive in such manner that they llareforwardly from the ends 32 to the ends 33. Furthermore the sections arearcuate or curved in cross section both on the outer and inner surfacesand are thus rendered hollow and comparatively thin as shown in Figureo. The opposite edges 3-1- of the sections thus formed are beveled andthese edges are glued or otherwise secured together throughout theirlengths so that the parts 85 of each of the sections between the edges34 bulge outwardly and the internal radius at the end 32 of each of thesections is similar to the radius ot the recess 26 on the blockextension 31. The individual sections can he glued with the ends 32fitting within the recess in so that when all the sections are joinedtogether as above described they will be securely t'astened to the blockextension 21 within the recess 26 and since the latter llares forwardlyit will be impossible for the resonator to pull away from the for- -ardend ot the extension 21 as is obvious from the showing of l i 'ure 2.Furthermore by havingthe part 25 projecting beyond the surtace 21 the.latter serves as an abutment oi aligning shoulder for sections. Each ofthe sections 28. 30 and.3i are cut t'roin a bloclr of wood in suchmanner as clearly shown in l igures 4 to ('5 inclusive that the grain islongest at the edges 34 and extends substantially parallel to said edges34- so that the laminations produced by the tihersot the gain becomeshorter at portions between the edges 34 and from the ends 82 to theends 3.; of each section. Thus each of the sections of the resonator hasintegral parts which will otter ditl'erent resistance against yieldingby sound waves tending to flex them. My shaping the sections and runningthe grain as above described and as illustrated tl 2 structure will bestitler at the edge portions 2M near the end 32 than at any otherportion owing to the greater tension on the longer fibers due to theextended adhering contact with adjacent fibers. From said portionsoutwardly from the end 32 and a way lrom the edges 34 the materialbecomes less stilt owing to the gradually increasing cross sectional arcand gradually shortcning libtrs.

With the above construction the amplifyingg resonator will be securelyheld at its rear portion only and will need no further support and inthis manner it is practically tree to vibrate at any portion t'orward ofits -onnection with the extension 21.

ii'e have described the resonator being composed of wood. However, itWill be understood that it desired this reso 1' may he made of othermaterial which has parts which will function similarly to said wood. Forexample it may be made of a material which is composed of laminations ofsimilar character to the fibers or layers of wood constituting the grainof the latter as above employed.

A resonator made in accordance with the above instead of focusing thesounds in one spot distributes the tone waves in a large radius andgives the impression that the sounds pass outwardly therefrom instead ofproducing the sensation that they are produced on the inside of theresonator as is usu ally the impression given by other resonators madeprior to our invention.

In the use of our invention the top of the block 15 may be connected inany suitable manner with a tone arm of a talking machine so that thesound transmitted will pass downwardly through the passage 16 thencethrough the transverse passage 19 and passage 23 into the amplifyingresonator 27. The construction of this resonator as previously describedis such that ithas portions of different resistances against vibrationso that the various length sound waves durin their passage through theresonator will find a sympathetic or suitably vibratory portionaccording to its resistance Within the substance of said resonator. Inthis manner as previously set forth in the objects of our invention areproduction of the sound Will be effected in such manner that therewill be no blurring or merging of the sounds and a correct reproductionof a record will be produced.

ll e preferably utilize two or more pairs of sections in constructingthe resonator so thateach pair includes the outwardly bulged sectionswhich are oppositely disposed and as illustrated We have employed foursections or in other words two pairs of sections and in this mannersimilarly constructed sections will be opposite each other and arrangedannularly around the longitudinal center or axis of the resonator. F orexample we preferably use a resonator including two, three or more pairsof the sections; each pair having its outwardly bulged portionsoppositely disposed.

While we have described our invention as taking a particular form, itwill be under stood that the various parts of our invention may bechanged without departing from the spirit thereof, and hence We do notlimit ourselves to the precise construction set forth, but consider thatwe are at liberty to make such changes and alterations as fairly comewithin the scope of the appended claims.

Having thus described our invention, What we claim as newand desire tosecure by Letters Patent is 1. A sound amplifier made of elongatedsections of laminated fibrous material in which the length of the fibersextend in the direction of the length of the sections, said sectionsbeing of arcuate cross section convex on the outer surfaces and concaveon the inner surfaces and flaring from one end to the other whereby thcross sectional arc in creases from one end to the other, the fibers ofthe sections being longest at the side edges and becoming graduallyshorterfrom portions between the side edges of each section adjacent thenarrow end toward the wide end, said side edges of the sections beingconnected together; substantially as described.

2. Sound amplifying means including supporting means having a soundconducting passage leading out through one end,

said end at its outer surface being circular in cross section; and aresonator made up of members which flare outwardly, the members at theirnarrow ends being of arcuate cross section having a common center andfitting concentrically around said surface of said end of the supportingmeans, said members beyond said small ends being curved to g meansimmediately in front of said shoulder, said members beyond said smallends being curved to form a substantially lobed cross section;substantially as described.

In testimony whereof we have signed our names to this specification inthe presence of two subscribing witnesses.

' HARRY J. DURBOROW.

BAYARD L. WINDERS.

Witnesses:

ANNA BENTON, CHAS. E. Po'rrs.

